Limitations Of OAI-NCSTRL Search Service

The current OAI-NCSTRL search engine has a few limitations:

1. Browsing by cluster (i.e., a search with no keywords, just cluster values) no longer
returns all members of a cluster. Only a partial list is returned. This is caused by
different authority file (subject, type, language, publication date) used by data
providers. Please be aware that browsing gives incomplete results.

We apologize for these limitations and we are working to resolve them by refinng the
search engine.

Help on Searching

Search for an document by seeking word matches on ALL
bibliographic fields or onSPECIFIC bibliographic
fields. You can specify how your search results will
be sorted.

Searching ALL bibliographic fields

The top of the search form presents a single text entry box. Enter keywords in this box
(e.g., digital library) to search the author, title, and abstract fields of the
bibliographic entries for all documents in the OAI-NCSTRL collection. The search returns
documents whose bibliographic entries contain all the words you entered in either the
author, title, type, language,,archive,subject, accession date, discovery date or abstract
fields. If you wish to enter a phrase, put it in quotes.

Sorting of results

There is a pulldown menu for either type of searching that allows you to specify the
sorting of search results. Search results can be sorted by rank, by accession
date, by archive. If there is a "tie" (e.g. there are many documents with
the same archive), the secondary sort is by Oracle
Intermedia search rank.

Grouping of results

There is a pulldown menu for choosing the manner in which the
results are to be grouped. Search results may be grouped according to Archive, accession
year, ,subject.

Rules for bibliographic keyword matching

Words that you enter in the three bibliographic keyword fields (Author, Title,
Abstract) are matched to bibliographic entries according to the following rules:

Each word that you enter matches any word in the respective field that begins with
respective word. For example, the word "comp" matches "computer",
"computation", "comprehensive", etc.

You may choose either the logical connector AND or OR between the
bibliographic keyword fields by using one of the radio buttons below the fields. For
example, if you select the or button and the word "robot" in the Title
field and "robotics" in the Abstract field, the search will return
documents that have either "robot" in their titles or "robotics" in
their abstracts. If you select the and button, the search will return only those
documents that have "robot" in their titles and "robotics" in their
abstracts.

You may also use logical connectors "and" and "or" within fields.
For example, if you enter "robotics or vision" in the abstract field, the
search will return documents that have the word "robotics" or "vision"
in their abstracts. If you enter "robotics and vision" in the abstract
field, the search will return documents that have both the word "robotics" and
"vision" in their abstracts. Multiple words that are not separated by
"and" are assumed to be "and" separated. For example, if you enter
"computer vision" in the abstract field, the search will return documents
that have both the words "computer" and "vision" in their abstracts.
Finally, you may use parentheses to group words. For example, if you enter "Gries or
(Teitelbaum and Field)" in the author field, the search will return documents
authored by "Gries" or by "Teitelbaum" and "Field".

Rules for advanced search

In this you may specify the author,the title or some keywords appearing in the
abstract. The search form below the three text entry fields for bibliographic keyword
entry, has two radio buttons to specify whether the field match specifications entered
should be "anded" or "ored" together.
To specify search criteria, enter keywords in one or more of the text entry boxes beside
the author, title and abstract labels (see the rules for bibliographic
keyword matching). A keyword may be a quoted phrase (e.g., "digital
library") to specify that the words should be contiguous.

Author - The author's first or last name or names .

Title - The words in the title of the document.

Abstract - The words in the abstract of the document.

and select the "AND" or "OR" radio button to indicate how you want
the different field search specifications to be combined.

Please note that not all documents in the collection have abstracts. If you want
your search request to include documents without abstracts, enter your search criteria
under Title as well as Abstract.

The filters provide a means by which a user can specify some details of the
document he is seeking.
The filters are

Archive - The entier digital library may be divided into archives depending on
the archive from which the document has been obtained. The different archive types are
descibed by their respective home pages whose links are provided at the footer of the
search form.

Archives Set - Archives may have sub collections in them this pull down
menu lets the user select the collection he wishes to search. by default it is
"All".

Subject - The user can also select the subject of the document he is searching.

Type - This lets the user specify what type of document he is searching. For
example if the document is a patent or a doctoral thesis.

DateStamp - A datestamp is the date of creation, deletion, or latest date of
modification of an item, the effect of which is a change in the metadata of a record
disseminated from that item.

Discovery Date -

Display Option

OAI-NCSTRL clusters

A Cluster is a collection of documents all of them sharing the same
value for a particular attribute. For example all the documents in the archive type xxx,
have the same attribute of the source digital library being that of XXX. This type of
organization of documents improves the searching capabilities of the digital library. This
allows users to specify the exact type of document they are looking for. For example a
user may wisht to view documents by a specific author which has been published in a
specific archive. This can be done by specifying the necessary filters.

Cluster information for Digital libraries

The entier document database has been indexed along
the following indices

ARCHIVE - This
specifies which is the original digital library from which the document has been obtained
eg.XXX

SET
- This specifies the collection from which teh document hails.

ABSTRACT
- The keywords of all the abstracts in the digital library are
indexed.

Working of the Advanced search

When the user types in the search string and a few
of the filter arguments, the search engine searches the respective indices for the matches
and retrieves the "sets" of document Id of the matches for that index and
then it does an intersection of these "sets" and displays its results
based on type of grouping (Eg. group by Archive type) that is expected by the user.